#include <windows.h>

HWND MainWindowHandle = 0;

bool InitWindowsApp(HINSTANCE instanceHandle, int show);

int Run();

LRESULT CALLBACK WndProc(HWND hWnd,
                          UINT msg,
                          WPARAM wParam,
                          LPARAM lParam);

int WINAPI WinMain(HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    PSTR pCmdLine,
                    int nShowCmd)
{
      if(!InitWindowsApp(hInstance, nShowCmd))
      {
           ::MessageBox(0, L"Init - Failed", L"Error", MB_OK);
           return 0;
      }

      return Run();
}

bool InitWindowsApp(HINSTANCE instanceHandle, int show)
{
      WNDCLASS wc;

      wc.style         = CS_HREDRAW | CS_VREDRAW;
      wc.lpfnWndProc   = WndProc;
      wc.cbClsExtra    = 0;
      wc.cbWndExtra    = 0;
      wc.hInstance     = instanceHandle;
      wc.hIcon         = ::LoadIcon(0, IDI_APPLICATION);
      wc.hCursor       = ::LoadCursor(0, IDC_ARROW);
      wc.hbrBackground =
           static_cast<HBRUSH>(::GetStockObject(WHITE_BRUSH));
      wc.lpszMenuName  = 0;
      wc.lpszClassName = L"Hello";

      if(!::RegisterClass(&wc))
      {
           ::MessageBox(0, L"RegisterClass - Failed", 0, 0);
           return false;
      }

      MainWindowHandle = ::CreateWindow(
                    L"Hello",
                    L"Hello",
                    WS_OVERLAPPEDWINDOW,
                    CW_USEDEFAULT,
                    CW_USEDEFAULT,
                    CW_USEDEFAULT,
                    CW_USEDEFAULT,
                    0,
                    0,
                    instanceHandle,
                    0);

      if(MainWindowHandle == 0)
      {
           ::MessageBox(0, L"CreateWindow - Failed", 0, 0);
           return false;
      }

      ::ShowWindow(MainWindowHandle, show);
      ::UpdateWindow(MainWindowHandle);

      return true;
}

int Run()
{
      MSG msg;
      ::ZeroMemory(&msg, sizeof(MSG));

      while(::GetMessage(&msg, 0, 0, 0))
      {
           ::TranslateMessage(&msg);
           ::DispatchMessage(&msg);
      }

      return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND windowHandle,
                          UINT msg,
                          WPARAM wParam,
                          LPARAM lParam)
{
      switch( msg )
      {
      case WM_LBUTTONDOWN:
    // можно тута че-нить для начала написать
    return 0;

      case WM_KEYDOWN:
           if( wParam == VK_ESCAPE )
                ::DestroyWindow(MainWindowHandle);
           return 0;

      case WM_DESTROY:
           ::PostQuitMessage(0);
           return 0;
      }

   return ::DefWindowProc(windowHandle,
                             msg,
                             wParam,
                             lParam);
}